Photosynthesis of plants growing in the sixth through ninth year of the BioCON FACE Experiment in Central Minnesota (USA) under conditions of "chronically low levels of nitrogen addition in a nutrient-poor prairie grassland"

49%

Ellsworth et al. (2004)

Plants grown under natural conditions for three years in a FACE study

100%

Lee et al. (2011)

Photosynthesis of upper fully-expanded young to mid-aged leaves of plants grown for 13 years in monoculture in the BioCON FACE experiment at the Cedar Creek Ecosystem Science Reserve in east central Minnesota (USA)